Electrical counting apparatus



June 3, 1969 J. s. LINDERMAN 3,448,252

ELECTRICAL COUNTING APPARATUS Original Filed June 18, 1963 Sheet 1 er simi 6 IECH. V mews g 1 60 4 \FILH 1 menu 99/00 A? smcn DETECTORI gg STEP2 I u n r V 47 n w'mkma 99/00 I DETECTOR 23 do w A FLASH LAMP -|4 fill'hiizm 54, e4 FLASH PULSE rucu TRIGGER TRANS- vomcs [AMPLIFIER FORMERSUPPLY a PULSE FLIP PULSE*P5$%%|":2 Q ucm SHAPER FLOP 8|FSHAPER DETECTORD B SOURCE I I I 52 as 14 5 as H, 4 JAMES STEPHENS LINDERMAN INVENI'ORATTORNEY J. s. LINDERMAN 3,448,252

ELECTRICAL COUNTING APPARATUS June 3, 1969 Sheet Original Filed June 18.1963 FIG. 4

FIG.3 Imm INVENTOR JAMES STEPHENS LINDERMAN PLANE l PATH FILI ATTORNEYSheet 0 of 3 INVENTOR JAMES STEPHENS LINDERMAN ATTORNEY June 3, 1969 J.s. LINDERMAN ELECTRICAL COUNTING APPARATUS Original Filed June 18, 1963United States Patent Ofi ice 3,448,252 Patented June 3, 1969 3,448,252ELECTRICAL COUNTING APPARATUS James Stephens Linderman, Wilmington,Del., assignor to E. I. du Pont de Nemours and Company, Wilmington,Del., a corporation of Delaware Original application June 18, 1963, Ser.No. 288,767, now Patent No. 3,263,581, dated Aug. 2, 1966. Divided andthis application Dec. 23, 1965, Ser. No. 515,861

Int. Cl. G06m J/22, l/27 U.S. Cl. 235-92 4 Claims This is a divisionalof application Ser. No. 288,767, filed June 18, 1963 now Patent No.3,263,581.

This invention relates to a film symbolizing device and, moreparticularly, it relates to a device for applying numbers or othersymbols along the length of photographic film.

The editing of various scenes taken on photographic cine film into acompleted motion picture requires that identification markings be placedbeside the picture area so that wanted sections can be located swiftlyand accurately. These identification marks have been standardized sothat they usually consist of a 6- or 7-digit number that is insertedbetween the perforations once per foot in an increasing or decreasingsequence. This identification means is called keynumbering by theindustry.

Although numbers can be printed on the film by using an inked printingwheel, the necessity of drying the ink is such a serious limitation thatit is seldom used. The method most commonly employed by the industryinvolves the optical exposure of numbers onto the film emulsion. Thismethod, of course, requires development of the emulsion before thenumbers are visible and, therefore, is referred to as Latent ImageKeynumbering.

Several latent image keynumbering systems that are known in the atrernploy an external light source that illuminates mechanical countingwheels similar to an odometer. Reflected light is collected in such amanner that the image of the illuminated numerals is projected to aplane containing the film. This approach is frequently inadequate due tothe difiiculty in obtaining sufficiently high contrast between thebright numerals and the surrounding dar'k area and because of mechanicalspeed and wear limitations imposed by the counting wheels. In addition,these mechanical counting wheels generally employ a cog and tootharrangement to advance the adjacent number disk when 9 or 99 comes up onthe first disk. Such an arrangement usually results in drift orinaccurate positioning of the numbers causing them to appear out ofline.

A satisfactory keynumbering system should be able to apply sharplydefined numbers at a very high speed (e.g., 1000 ft./min.) at a preciselocation between perforations. Further, the system should have a highdegree of reliability and require little supervision during operation.

These and other objects and advantages are accomplished in accordancewith this invention which is particularly pointed out in the appendedclaims and is illustrated, in its preferred embodiments, in theaccompanying drawings wherein:

FIG. 1 is a schematic illustration of a latent image keynumbering systemaccording to this invention wherein the size and spacing of certainelements are deliberately distorted for the purposes of clarity.

FIG. 2 is a sectional elevation view of the device employed to projectsymbols according to the invention.

FIG. 3 is a plan view of a preferred symbolizing device according to theinvention.

FIG. 4 is a front elevation view of the device shown in FIG. 3.

FIG. is a circuit diagram of the electrical components employed in theinvention.

Referring now to the drawings, the keynumbering device illustratedoperates on the principle of projecting numbering images on a movingfilm between the perforations thereof once per foot. A flash lamp 10 isprovided which is located within stationary lamp housing 11 on the axisof three concentric rotary drums 12, 13 and 14. The surfaces of thesedrums are covered with an opaque material 12a, 13a, 13b and 14a as shownin FIG. 2 and a series of transparent numbers from 00 to 99 are producedthereon by etching through the opaque material. The numbers arepositioned in a circumferential row on each drum, equally spaced fromone another and occupying the entire circumference. The three rows arepositioned closely adjacent to one another, so that conjointly theyproduce six-digit numbers, one of which is imaged as later describedonto the film surface. Drum 12 is tightly fit onto collar 15 whichfreely rotates on bearings 16 and 17 and has spur gear 18 connectedthereto. By engagement of the latter with gear reducing means 19, 20 and21, drum 12 is driven from the main mechanical drive at such a rate thatthe surface numbers are advanced once per foot of film travel. Drums 13and 14 are driven only by step motors 22 and 23 respectively through thegear drive arrangement depicted in FIG. 2. Step motor 22 is connected toend plate 24 (by means not shown) and directly drives spur gear 25 whichtogether with spur gear 26 is mounted on shaft 27 in sleeve bearings 28and 29. Drum 13 is tightly fit onto collars 30 and 31 which rotatefreely about lamp housing 11 on bearings 32 and 33, respectively. Collar31 has ring gear 34 attached thereto whose internal teeth are engaged byspur gear 26 thereby enabling step motor 22 to drive drum 13. Step motor23 is also connected to end plate 24 (by means not shown) and directlydrives internally toothed ring gear 35 which is attached to collar 36which has drum 14 tightly fit thereon. The collar 36 freely rotates inbearings 37 and 38 about end block 39 which is held to light housing 11and end plate 24 by bolt 40'. End plate 24 together with keeper ring 41mounted on light housing 11 hold the assembly together. The lighthousing 11 contains openings 42 and 43 and has a mirror-surface member44 attached thereto by capscrew 45. The flashes of light from bulb 10strike the surface of member 44 and are projected out through opening 43onto the interiors of drums 12, 13 and 14. The latter are made of atranslucent material but have opaque surfaces 12a, 13a and 13b exceptfor the circumferential bands of numbers etched thereon. For thisreason, the only light transmitted therethrough toward the film will bein the form of number images, and these are focussed upon the film by anoptical system 52 to be described later. The light ray axis is depictedby the broken line arrows.

Step motors 22 and 23 are actuated only by 99/00 detectors 46 and 47.The latter are light sensitive phototransistors such as Photons(manufactured by the Solid State Products Co.) which, when connected asshown in FIGURE 5, produce an output impulse responsive to light beamsincident thereon. These light beams are created by placing apertures 48and in surface 12a and aperture 49 in surface 13b of drums 12 and 13 insuch a location that aperture 48 on drum 12 will be aligned withdetector 46 permitting a light beam to strike the latter at such timethat the number-image light *beams directed at the film through drum 12is at number 99 for an increasing series of numbers or at 00 for adecreasing series of numbers. This selection is made by mechanicallyrepositioning detectors 46 and 47. Similarly, drum 13 contains aperture49 and drum 12 contains aperture 80 which are so located that they willbe in alignment With detector 47 permitting a light beam to strike thelatter at the time both drums 12 and 13 are in positions at which.number 99 is directed at the film from each drum for :an increasingnumber sequence and number is directed at the film for a decreasingnumber sequence.

The eifect of such an arrangement is to direct light from bulb offmirror surface 44 through opening 43 :at the drums 12, 13 and 1-4. Atthe beginning of operation, it is assumed that :the drums are allpositioned such that the numbers 00 will be directed at the film fromeach drum. As the main mechanical drive commences to advance to film androtate drum 12, the numbers 01 through 99 are consecutively focused atthe film, while drums 13 and 14 remain unmoved and therefore permit onlynumbers 00 to be directed therefrom. When drum 12 has advanced to theposition where number 99 is directed at the film, then aperture 48 is inalignment with detector 46. When bulb 10 flashes detector 46 receives animpulse of light that is converted into an electrical signal thatadvances step motor 22 one position. The latter, on receipt of thisimpulse, advances drum 13 one position such that the number 01 is nowbeing directed therefrom at the film. When both drums 12 and 13 are attheir 99 position, detector 46 will actuate motor 22 as previouslydescribed and detector 47 will receive a light beam through apertures 49and 80 which are now in alignment. Detector 47 will then actuate stepmotor 23 to advance drum 14 one position so that the number 01 is nowbeing directed therefrom. The operation continues so that drum 12 iscontinuously revolved by the main mechanical drive at a rate of onenumber per foot of film travel. Drum 13 is advanced one number percomplete revolution of drum 12 and drum 14 is advanced one number percomplete revolution of drum 13.

Referring now specifically to FIGS. 3 and 4, the symbol projectingdevice depicted in FIG. 2 is located within housing 50 being fastenedthereto by capscrew 51 which engages the end plate 24. The number-imagesare projected out through optical system 52 which is equipped with ashutter 53 and two lenses and focussed upon the film plane shown. The99/00 detectors 46 and -47 are mounted to the housing 50 as shown; theyare so mounted that they may be shifted in the direction tangential tothe drums the distance of one number for reasons to be explainedhereafter. The housing also contains printed circuit cards 54(containing the flash trigger amplifier) and 55 (containing the 99/00detector circuits); these electronic components are shown in FIG. 5.

Housing 50 has four openings 73, two being located on each of the twovertical faces. One on each face is opposite gear 18, such that gear 21is admitted through the housing for meshing with gear 18, and such thatgear 58, the purpose of which will be explained later, is admitted tomesh with gear 59, when the housing is turned 180. The other opening oneach face is positioned to admit gear 58 when gear 21 is meshed withgear 18 and, in the 180 position, to admit gear 21 when gear 58 ismeshed with gear 59.

While the device has been described above in connection with numberingfilm in ascending order, it can also be used to number the film indescending order. For eX- ample, housing 50 is releasably held in placewith contact between gears 21 and 18, on V-rails 56 and 57 for numberingin ascending order as shown on FIGURE 3. For numbering in descendingorder, the housing 50 is turned around 180 so that gear 58 turns spurgear 18 through idler gear 59. The latter may be suitably supported bymeans readily apparent to one skilled in the art but omitted from thedrawings for the sake of clarity. This shift in operation will have theeffect of rotating drum 12 in the opposite direction so that the numberimages are projected in descending order (i.e., from 99 downward). Withthis type of operation the detectors 46 and 47 must be shifted asdescribed above so that the actuation of the step motors will properlyoccur when drum 12 is aligned for projection of number 00 (rather thanfor projection of number 99 as in the case for numbering in ascendingorder). Simultaneously with reversal of housing 50, the direction ofrotation of step motors is switched automatically as described below.

The housing 50 also carries two electrical terminal sets in the form ofplugs 71 and 72, one of which meshes with a receptacle 70 carried on theface of the machine from which support and alignment rails 56 and 57project. In one of the two positions of housing 50, plug 71 is in use,carrying power and signal to the components within housing 50. In theother position, plug 72 is in use. The wiring to the plugs from thestepping motors, and the wiring associated with the receptacle 70 isarranged so that reversal of housing 50 causes reversal of the directionof rotation of the stepping motors.

An important aspect of the invention is the means by which the flashlamp 10 is actuated. A microswitch 60 is mechanically actuated by cam 61connected to the main mechanical drive in such a manner that switch 60produces an electrical output once per foot of film travel. However,this impulse being mechanically produced is not precise enough to beused alone to trigger the flash lamp 10 such that the flashes could bewell coordinated with respect to the perforations of the film. For thisreason a perforation synchronization detector 62 is provided whichproduces an impulse responsive to the pulses of light that are receivedfrom a light source directed through the moving perforations of thefilm. Specifically, the system employs a photodetector 62 "beneath theperforation track of the film and a spot of light directed at the trackfrom the opposite side. When a perforation passes, the light is allowedto reach the detector; between perforations light is blocked from thedetector. Detector 62 and pulse shaper 81 generate an electrical signalwhose voltage is in one of two states depending on Whether light isblocked by the film or passed by the perforations. This waveform is usedto synchronize the flashing of lamp 10 as described below. A flip flopcircuit 63 is provided which receives the pulse from the microswitch 60at the rate of once per foot of film travel. This pulse, however, canonly be released from the flip flop upon receipt of the synchronizingpulse from the perforation synchronization detector 62. In this mannerthe output from the flip flop circuit is regulated both with respect tofilm travel and location of perforations. The flash lamp 10 is a gaseousdischarge lamp which has a high voltage impressed thereon. The lamp andits trigger circuitry is a commercial unit of which Model FX-3l made byEdgerton, Germeshausen, & Grier, Inc., Boston, Massachusetts, is anexample. The voltage on the lamp is maintained just beneath thethreshold value at which the gas will ionize so that firing is onlyaccomplished when the additional voltage pulse is received from theflash trigger circuit 54 via pulse transformer 64. In this way theillumination of the flash lamp 10 is regulated by the output of the flipflop circuit 63 with the result that numbers are directed at the film inprecisely the proper locations between the perforations.

. Specifically, the output pulse from flip flop 63 is directed intohousing 50 through receptacles 71 or 72 to flash trigger circuit 54.This input pulse is amplified by transistor A and coupled to a pulseamplifier consisting of four-layer diodes B and C. These diodes (similarto Type 4E20, manufactured by Shockley Semiconductor Co.) remain in thenonconducting or high-impedance state until the input pulse fromamplifier A causes the voltage across diode -B to exceed 20 volts. Atthis time, diode B switches to a low-impedance and simultaneously diodeC switches to a low impedance causing a positive voltage pulse to beapplied to pulse transformer 64 through coupling capacitor D. Shortlyafter the pulse has been coupled to the pulse transformer diodes B & Creturn to the high-impedance state so that the circuit is ready for thenext flash trigger. Pulse transformer 64 converts the 28 v. flashtrigger pulse to a pulse several hundred volts in amplitude such thatthe arc in the flash lamp can be initiated.

The 99/00 detectors 46 and 47 and the 99/00 detector circuit card 55contain the electronic circuitry needed to provide an electrical pulseto stepping motors 22 and 23. In both cases light from lamp is allowedto fall on the 99/00 detector when the rotating drums 12 and 13 areproperly oriented. This light flash causes detector 46 to change from ahigh-impedance state to a low-impedance state. Energy is then allowed toflow through the detector to the stepping motor 22. Once detector 46 hasreached its low-impedance state, it remains there until an externalpulse generating circuit supplies sufi'icient power to reverse thecurrent flow through the detector. This external pulse generation isaccomplished by four-layer diode F similar to diodes B and C above. Uponinitiation of power flow to stepping motor 22, voltage slowly risesacross the four-layer diode. This diode remains in the high-impedancestate until the applied voltage exceeds 20 v. At this time, it breaksdown to a low impedance. The resulting voltage pulse is coupled throughcapacitor 89 to the 99/00 detector 46 reversing its current andreturning it to the high-impedance state. Current through four-layerdiode F decreases exponentially until it is less than the requiredholding current of the device and then the diode returns to itshigh-impedance state. The cut off of detector 47 is similarly controlledby 4-layer d iode E.

Diodes 82 and 83 serve to ground reverse-voltage pulses from theinductive kick of the stepping motor windings at the moment of switchingofi the detectors 46 and 47. Resistors 84, 85, 86 and 87 together withcapacitors 88, 89, 90 and 91 regulate the rate of voltage buildup toshut 0c detectors 46 and 47.

This invention overcomes the inherent disadvantages of otherkeynumbering systems. The use of transparent number masks of cylindricalform (i.e., the drums) with a light source mounted on the cylindricalaxis completely eliminates background exposure around the number andmaintains high contrast. The high optical efiiciency of thistransmission system compared with existing methods, allows use of aflash lamp with low energy output, fast duration, and long life. Thiseliminates the blurring obtained from longer exposures and results in asimultaneous improvement in reliability.

The flash of the light source must be precisely synchronized withlocation of the film perforations so that the numbers remain centered.At 1000 ft./min., of film travel this synchronization must be maintainedwithin i100 as. Previous systems have used electrical breaker points onsprocketed film rollers to provide synchronization. This approach is notprecise enough for proper number appearance and results in extremelydifiicult maintenance and frequent failure. In the present system, theseparate optical detector system provides location information within 10,uS. This optical-electronic unit detects the presence or absence of aperforation and generates from this an accurate position synchronizationpulse.

The embodiments of the invention in which an eX- clusive property orprivilege is claimed are defined as follows:

1. A counter comprising first and second drums, the

surfaces of which have a circumferential series of translucent symbolslocated thereon said first drum having a specific translucent aperturein addition to said symbols, a light source located within said drums,means for driving said first drum, a step motor for drving said seconddrum and means for actuating said step motor upon receipt of a lightbeam emanating from said light source through said aperture on the firstdrum.

2. A film counting device comprising first and second drums, thesurfaces of which have a circumferential series of translucent symbolslocated thereon, a light source located within said drums synchronizedto flash with the passage of said film, means for driving said firstdrum, a step motor for driving said second drum, and means to actuatesaid step motor by signalling said motor upon receipt of a light beampassing through said first drum at a designated symbol on the surface ofsaid first drum.

3. A device for counting the length of a film comprising means formoving said film past said device, first and second drums the surfacesof which are substantially opaque, each surface having a circumferentialseries of translucent symbols located thereon, said first drum having aspecific translucent aperture on its surface to pass a light beam onceduring a sequence of said symbols, a flashing light source locatedwithin said drums, means for driving said first drum in synchronizationwith said film movement, a step motor for driving said second drum, andmeans for actuating said step motor upon receipt of a light beamemanating from said light source through said specific aperture on thefirst drum.

4. A device adapted for a perforated film latent key number markingapparatus having a counter, a light source, means for passing said filmand projection means for projecting symbols from said counter to thefilm area between the perforations of said film, said device comprisingfirst and second drums the surfaces of which are substantially opaque,each surface having a circumferential series of translucent symbolslocated thereon, said first drum having a specific translucent apertureon its surface to pass a light beam when said drum is in a selectedposition, a flashing light source located within said drums, means fordriving said first drum in synchronization with said film passage, astep motor driving said second drum, and means for actuating said stepmotor upon receipt of a light beam emanating from said flashing lightsource through said specific aperture on the first drum.

References Cited UNITED STATES PATENTS 1,948,319 2/1934 Spence l.12,131,911 10/1938 Ayres 235-92 2,945,624 7/1960 Nicolaus 235-1333,046,857 7/1962 Kargl 95l.1 3,248,526 4/1966 Goldberg 235-92 3,263,5558/1966 Scheib 951.1

MAYNARD R. WILBUR, Primary Examiner. GREGORY J. MAIER, AssistantExaminer.

1. A COUNTER COMPRISING FIRST AND SECOND DRUMS, THE SURFACES OF WHICHHAVE A CIRCUMFERENTIAL SERIES OF TRANSLUCENT SYMBOLS LOCATED THEREONSAID FIRST DRUM HAVING A SPECIFIC TRANSLUCENT APERTURE IN ADDITON TOSAID SYMBOLS, A LIGHT SOURCE LOCATED WITHIN SAID DRUMS, MEANS FORDRIVING SAID FIRST DRUM, A STEP MOTOR FOR DRIVING SAID SECOND DRUM ANDMEANS FOR ACTUATING SAID STEP MOTOR UPON RECEIPT OF A LIGHT BEAMEMANATING FROM SAID LIGHT SOURCE THROUGH SAID APERTURE ON THE FIRSTDRUM.